Simple Mechanical Ventilation System for a Small House
Remodeler Joshua Oduin explains how the Lunos E2 HRV system works, why it's a good source of fresh indoor air for small spaces, and how easy it is to install.
In this episode of Job-Site Diaries, Josh Oduin is back in Leavenworth, WA, to talk about adding a heat-recovery ventilator (HRV) to provide balanced ventilation in his new cabin. Josh walks through his reasoning behind why he chose the Lunos E2 HRV over a typical ducted system. He gives a brief overview of how the units work, and demonstrates the basic steps of installation.
The Lunos E2 is a brilliantly simple collection of components, with most of the work being done by a constantly reversing pair of fans and heat exchangers, eliminating the need for the complicated heat transfer components found inside a typical HRV.
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I installed a pair of Lunos e2's in my house this spring. They've been running constantly for 2 months. I've been really happy with them. The fans are really quiet, and the one installed above our bed hasn't affected our sleep. They're not cheap, at nearly $1100 per pair but compared to a ducted HRV system that I also looked into, the cost was much less. I live in a 1970's house in Bend, OR with 2x4 walls. I've spent a good deal of time these past few years air sealing the house and wanted a way to bring in some fresh air, esp. during the winter and when we have to close the windows for the smoke from summer wildfires. With "thinner" walls the fan tubes will stick out into your room a few inches so building some type of enclosure will be necessary for a nice look. I ended up frame a wood box from CVG fir around the tubes for the coverplate to attach to. I'd recommend using the Roflex gaskets that 475 sells, they made for a bomber air seal. I also used the rotary switch and like the simplicity and design. 475's customer service was great and they helped answer a bunch of my questions and walked me through the correct placement of the fans for our house.
I'm on Southern Vancouver Island. Wet winters, but not overly humid in the summer. My experience has been somewhere in between yours and Joshua's. I haven't seen problems with either HRVs or unconditioned ventilation since it was mandated in all new houses several years ago. But I've never been able to get indoor humidity below the high 40s by introducing outdoor air. An insulated, heated space without occupant activity adding moisture, like my wife's shed, tracks the RH of our house within a couple of % points as stated on your website.
I think maybe there was a mistake in the video towards the end. He said there was a "Dedicated circuit". Surely something that pulls such low current does not require a dedicated circuit. Perhaps he meant dedicated outlet/box?
I've installed the Lunos system in my 800 sq ft home and am excited to see how it performs. The build quality seems high, but at $1100 I can't help but feel I overpaid for something very simple. I'm sure as competitors enter the market the price will drop dramatically.
Also, call me crazy, but for that price I feel like the Roflex gaskets and rotary switch should be standard. After you drop over a grand on a pair of fans it feels pretty lame to have to buy "extras".
Leavenworth is a beautiful place, what a great location to build a cabin in the woods.
"balancing the moisture between outside and inside" - I get confused on these points a lot. An ERV balances/exchanges moisture between interior and exterior while an HRV does not. It could be that the HRV would "balance" moisture in the house by bringing in humid outdoor air, but I think leavenworth has a pretty dry climate. I live in the same zone, 5B, and have been told that ERVs are preferred to maintain winter time humidity levels at comfortable levels (from getting too dry and cracking skin).